Expansion of tubular elements finds increasing use in the industry of hydrocarbon fluid production from an earth formation, whereby boreholes are drilled to provide a conduit for hydrocarbon fluid flowing from a reservoir zone to a production facility to surface. Conventionally such borehole is provided with several tubular casing sections during drilling of the borehole. Since each subsequent casing section must pass through a previously installed casing section, the different casing section are of decreasing diameter in downward direction which leads to the well-known nested arrangement of casing sections. Thus the available diameter for the production of hydrocarbon fluid decreases with depth. This can lead to technical and/or economical drawbacks, especially for deep wells where a relatively large number of separate casing sections is to be installed.
To overcome such drawbacks it has already been practiced to use a casing scheme whereby individual casings are radially expanded after installation in the borehole. Such casing scheme leads to less reduction in available diameter of the lowest casing sections. Generally the expansion process is performed by pulling, pumping or pushing an expander cone through the tubular element (such as a casing section) after the tubular element has been lowered into the borehole. However the force required to move the expander cone through the tubular element can be extremely high since such force has to overcome the cumulated expansion forces necessary to plastically deform the tubular element and the frictional forces between the expander cone and the tubular element.
EP-0643794-A discloses a system for expanding a tubular element using a tool movable between a radially retracted mode and a radially expanded mode. The tubular element is expanded in cycles whereby in each cycle the tool is positioned in a portion of the tubular element whereby the tool is in the retracted mode, and subsequently the tool is expanded thereby expanding said tubular element portion in a single step. Next the tool is to be repositioned accurately in the tubular element before the expansion cycle can be repeated.